Hi.. Can understand your concern.. As per your complain it is true that filling in lower teeth do not cause pain in upper gums although on the same side.. It can be due to either any infected tooth in which the infection is located on the side wall of tooth which is located in between two teeth and is many times missed out during clinical examination as it is not visible in the mouth. It can be ruled out by taking x rays of teeth located in the are where there is pain. Other reason can be infection in gums which can lead to pain, swelling and bleeding from gums. It is also likely that if you have sinusitis problem in that case inflammation of maxillary sinus on effected side can also lead to pressure and soreness of gums along with other symptoms of sinusitis. I would suggest you to consult your dentist and get x rays done of teeth on effected side to find out any problem associated with teeth , gums and adjoining structures like jaw bone. If no dental problem is ruled out you can once consult an ENT expert to get checked for any sinus problem.. Hope your query is solved.. Thanks and regards.. Dr.Honey Nandwani Arora.